US7124264B2 - Storage system, control method for storage system, and storage control unit - Google Patents

Abstract

The present invention relates to a storage system, including a first storage unit having a first storage volume for storing data, and a second storage unit having a second storage volume communicably connected with the first storage unit, wherein the first storage unit further comprises a replication data transmission unit for transmitting the replication of data to a second storage unit when the data is written to the first storage volume, the second storage unit further comprises a replication data reception unit for writing the replication of the data transmitted by the replication data transmission unit to the second storage volume, the first storage unit further comprises a disk heart beat write unit for repeatedly writing a first heart beat message to the first storage volume at intervals within a predetermined time, and the second storage unit further comprise a disk heart beat detection unit for detecting the replication of the first heart beat message to be written to the second storage volume by the replication data reception unit.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application relates to and claims priority from Japanese Patent Application No. 2004-002037, filed on Jan. 7, 2004, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a storage system, a control method for a storage system, and a storage control unit.

2. Description of the Related Art

In order to avoid the loss of data stored in a storage unit constituting a computer system when such a disaster as an earthquake occurs, a technology called “replication” is used in the recent advances of information technology. Replication is a technology for storing the replication of data, which is stored in a storage volume of a storage unit of a computer system at a main site, to a storage volume in a storage unit of a storage system at a remote site.

In the case when a computer system at a remote site detects that the computer system at the main site has shut down, a technology for the computer system at the remote site to “take over” the information processing that the computer at the main site has been executing was developed.

The information processing unit of the computer system at the main site repeatedly transmits a predetermined data called a “heart beat message” to the computer system at the remote site at intervals within a predetermined time. A technology to transmit this heart beat message using replication technology was also developed.

In this case, the computer system at the remote site detects the interruption of transmission of the heart beat message from the main site, by which the occurrence of an abnormality to the computer at the main site is detected. However, when the transmission of the heart beat message from the main site is interrupted by an abnormality of the storage unit at the main site, the computer system at the remote site cannot specify that it is the storage unit at the main site where the abnormality occurred.

SUMMARY OF THE INVENTION

With the foregoing in view, it is an object of the present invention to provide a storage system, a control method for a storage system, and a storage control unit.

To solve the above problem, the present invention relates to a storage system, comprising a first storage unit that has a first storage volume for storing data, and a second storage unit that is connected communicably with the first storage unit and has a second storage volume for storing data, wherein the first storage unit further comprises a replication data transmission unit for transmitting the replication of data to the second storage unit when the data is written to the first storage volume, the second storage unit further comprises a replication data reception unit for receiving the replication of the data transmitted by the replication data transmission unit and writing the replication of the data to the second storage volume, the first storage unit further comprises a disk heart beat write unit for repeatedly writing a first heart beat message to the first storage volume at intervals within a predetermined time, and the second storage unit further comprises a disk heart beat detection unit for detecting the replication of the first heart beat message to be written to the second storage volume by the replication data reception unit.

In this case, it is also possible that a first information processing unit is communicably connected to the first storage unit and a second information process unit is communicably connected to the second storage unit, the first information processing unit further comprises a node heart beat write request unit for repeatedly transmitting a request to write a second heart beat message to the first storage volume, to the first storage unit at intervals within a predetermined time, the first storage unit further comprises a node heart beat write unit for writing the second heart beat message to the first storage volume according to the write request of the second heart beat message, the second storage unit further comprises a node heart beat transmission unit for transmitting the replication of the second heart beat message, to be written to the second storage volume by the replication data reception unit, to the second information processing unit, and the second information processing unit further comprises a node heart beat detection unit for detecting the replication of the second heart beat message to be transmitted by the node heart beat transmission unit.

The first heart beat message is also referred to as a “disk heart beat signal”, and the second heart beat message as “node heart beat signal” herein below.

Problems that the present application discloses and the solutions thereof will be clarified through the preferred embodiments and drawings.

The present invention can provide a storage system, a control method for a storage system, and a storage control unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram depicting the general configuration of a storage system according to the present embodiment;

FIG. 2 is a block diagram depicting the configuration of an information processing unit according to the present embodiment;

FIG. 3 is a block diagram depicting the configuration. of a management console according to the present embodiment;

FIG. 4 is a diagram showing a pair management table according to the present embodiment;

FIG. 5 is a block diagram depicting the general configuration of a storage system according to the present embodiment;

FIG. 6 is a diagram showing an activation/deactivation message according to the present embodiment;

FIG. 7 is a diagram showing a heart beat status table according to the present embodiment;

FIG. 8 is a diagram showing a heart beat signal according to the present embodiment;

FIG. 9 is a flow chart depicting the flow of activation processing of a heart beat signal according to the present invention;

FIG. 10 is a flow chart depicting the flow of deactivation processing of a heart beat signal according to the present embodiment;

FIG. 11 is a flow chart depicting the flow of transmission processing of a node heart beat signal according to the present embodiment;.

FIG. 12 is a flow chart depicting the flow of transmission processing of a disk heart beat signal according to the present embodiment;

FIG. 13 is a flow chart depicting the flow of reception processing of a disk heart beat signal according to the present embodiment;

FIG. 14 is a flow chart depicting the flow of reception processing of a node heart beat signal according to the present embodiment;

FIG. 15 is a diagram showing a heart beat decision table according to the present embodiment;

FIG. 16 is a block diagram depicting the general configuration of a storage system according to the present embodiment;

FIG. 17 is a diagram showing heart beat decision table according to the present embodiment;

FIG. 18 is a block diagram depicting the general configuration of a storage system according to the present embodiment;

FIG. 19 is a diagram depicting a heart beat decision table according to the present embodiment;

FIG. 20 is a block diagram depicting the general configuration of a storage system according to the present embodiment;

FIG. 21 is a diagram showing a heart beat decision table according to the present embodiment;

FIG. 22 is a diagram showing a heart beat decision table according to the present embodiment; and

FIG. 23 is a diagram depicting the status when the operation status of the computer system is output to a user interface according to the present embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

General Configuration Example

FIG. 1 shows a block diagram depicting the general configuration of astorage system400 according to the present invention.

Thestorage system400 according to the present invention is comprised of an information processing unit A (first information processing unit)100, storage unit A (first storage unit)200, information processing unit B (second information processing unit)100 and storage unit B (second storage unit)200.

The information processing unit A (100) and the storage unit A. (200) constitute a computer system (first computer system) installed at a main site (primary site). The information processing unit B (100) and the storage unit B (200) constitute a computer system (second computer system) installed at a remote site (secondary site).

The information processing unit. A (100) is an information equipment for providing various information processing services using the storage resources provided by thestorage volume230 of the storage unit A (200). The information processing services provided by the information processing unit A (100) are, for example, automatic deposit/withdrawal services of a bank and seat reservation services of an airline. The location where the information processing unit A (100) and the storage unit A (200) are installed is called a “main site”.

Thestorage volume230 is a storage area for storing data, and includes a physical volume, that is a physical storage area provided by a hard disk drive, for example, and a logical volume, that is a storage area which is logically set on the physical volume.

The information processing unit B (100), on the other hand, is an information equipment for taking over the information processing service, which the information processing unit A (100) installed at the main site has been executing, when the information processing unit A (100) cannot provide the information processing service due to a disaster, for example. At this time, the information processing unit B (100) provides the information processing service by using the storage resources provided by thestorage volume230 of the storage unit B (200). For this, the replicated data stored in thestorage volume230 of the storage unit A (200) is also stored in thestorage volume230 of the storage unit B (200). To store the replication of the data stored in the storage unit A (200) in the storage unit B (200), replication control is executed. When replication control is executed, data is written to thestorage volume230 of the storage unit A (200), then the storage unit A (200) transmits the replicated data to the storage unit B (200). The storage unit B (200) receives the replicated data which is transmitted from the storage unit A (200), and writes the replicated data to the storage volume203 of the storage unit B (200). The replication control will be described later. The location where the information processing unit B (100) and the storage unit B (200) are installed is called a “remote site”.

The information processing unit B (100) not only takes over the information processing service provided by the information processing unit A (100), but also may provide its own information processing service. In this case, when the information service cannot be provided by the information processing unit B (100) due to a disaster, for example, the information processing unit A (100) may take over the information processing service provision. In this case, for both of these two computer systems, the local computer system becomes a computer system installed at a main site, and the other computer system becomes a computer system installed at a remote site. Here, however, to simplify description, the location where the information processing unit A (100) and the storage unit A (200) are installed is regarded as the main site, and the location where the information processing unit. B (100) and the storage unit B (200) are installed is regarded as the remote site.

The information processing unit A (100) installed at the main site and the information processing unit B (100) installed at the remote site are communicably connected via thefirst network300. The storage unit A (200) installed at the main site and the storage unit B (200) installed at the remote site are communicably connected via thesecond network310. The above mentioned replication control is executed by transmitting the replication of the data via thesecond network310. The information processing unit A (100) and the storage unit A (200) are communicably connected via the input/output path A-330. The information processing unit B (100) and the storage unit B (200) are also communicably connected via the input/output path B-330.

Thefirst network300 can be a LAN (Local Area Network or a WAN (Wide Area Network based on TCP/IP (Transmission Control Protocol/Internet Protocol) communication protocol, for example.

Thesecond network310 can be a SAN (Storage Area Network) where communication is performed by fiber channel communication protocol, for example. The input/output path330 can be a SAN where communication is performed by fiber channel communication protocol, for example. Certainly such communication protocols as FICON (Fiber Connection) (Registered Trademark), ESCON (Enterprise System Connection) (Registered Trademark), ACONARC (Advanced Connection Architecture) (Registered Trademark), FIBARC (Fiber Connection Architecture) (Registered Trademark) and iSCSI (internet Small Computer Systems Interface) can be used. By connecting the storage unit A (200) and the storage unit B (200) by thesecond network310 using such a highly reliable communication protocol, data transmission/reception between the storage unit A (200) at the main site and the storage unit B (200) at the remote site can be performed with high reliability.

Information Processing Unit

FIG. 2 is a block diagram depicting the configuration of theinformation processing unit100 according to the present embodiment. Theinformation processing unit100 according to the present embodiment includes the information processing unit A (100) and the information processing unit B (100), but both are referred to asinformation processing unit100 unless a distinction is required, since the basic configuration thereof is the same.

Theinformation processing unit100 is comprised of aCPU110,memory120,port130, recordingmedium reading unit140,input unit150,output unit160 andstorage unit170.

TheCPU110 is in-charge of the overall control of theinformation processing unit100, and provides the above mentioned various information processing services by executing theapplication programs190 stored in thememory120. TheCPU110 also executes the heart beatcontrol program191, node heart beatprogram192,storage management program193,clustering control program196 andoperating system197 which are comprised of codes for performing various operations according to the present embodiment.

For example, the operation status decision unit and the operation status display unit are implemented by theCPU110 executing the heart beatcontrol program191. Also the node heart beat write request unit, node heart beat detection unit and node heart beat creation unit are implemented by theCPU110 executing the node heart beatcontrol program192, for example. Also the fail over control unit is implemented by theCPU110 executing theclustering control program196, for example. In thememory120, the heart beat status table194, activation/deactivation message195 and heart beat decision table198 are stored. Details on these will be described later. The heart beatcontrol program191, node heart beatcontrol program192,storage management program193,clustering control program196 andoperating system197 may be independent programs, or at least a part of these programs may be constructed by a same program. Each program may be comprised of a plurality of programs.

The recordingmedium reading unit140 is a unit for reading programs and data recorded in therecording medium170. The programs and data which are read are stored in thememory120 or thestorage unit170. Therefore the heart beatcontrol program191, node heart beatcontrol program192,storage management program193,clustering control program196 andoperating system197, which are recorded in therecording medium170, for example, can be read from therecording medium170 using the recordingmedium reading unit140, and can be stored in thememory120 or thestorage unit180. For therecording medium170, a flexible disk, magnetic tape, CD-ROM and semiconductor, for example, can be used. The recordingmedium reading unit140 may be built into theinformation processing unit100 or may be external. Thestorage unit180 is a hard disk unit or a semiconductor storage unit, for example. The heart beatcontrol program191, node heart beatcontrol program192,storage management program193,clustering control program196,operating system197, heart beat status table194, activation/deactivation message195 and heart beat decision table198, for example, may be stored in thestorage unit180.

Theinput unit150 is a user interface used for data input to theinformation processing unit100 by an operator. Theinput unit150 can be, for example, a keyboard or a mouse. Theoutput unit160 is a user interface used for output information. For the outunit160, a display or a printer, for example, can be used. Theport130 is a unit for executing communication. For example, communication with anotherinformation processing unit100 which is performed via thefirst network300 and the transmission of data input/output request to thestorage unit200 may be executed via theport130. Also theapplication program190, heart beatcontrol program191, node heart beatcontrol program192,storage management program193,clustering control program196 andoperation system197, for example, may be received from anotherinformation processing unit100 via theport130, and stored in thememory120 or thestorage unit180.

Storage Unit

Thestorage unit200 according to the present embodiment will now be described with reference toFIG. 1. Thestorage unit200 according to the present embodiment includes the storage unit A (200) and the storage unit B (200), but both are referred to asstorage unit200 unless a distinction is required, since the basic configuration thereof is the same.

Thestorage unit200 is comprised of a disk control unit (storage control unit)210, adisk drive unit220 and amanagement console260.

Thedisk control unit210 performs communication with theinformation processing unit100 and anotherstorage unit200, and controls the read/write of the data to thestorage volume230 of thedisk drive unit220. For example, thedisk control unit210 receives a data write request from theinformation processing unit100, and executes data write processing for thestorage volume230 of thedisk drive unit220.

Thedisk control unit210 is comprised of aCPU211,memory212, FC I/F (Fibre Channel Interface)213, and disk I/F (disk interface)214.

TheCPU211 is in-charge of general control of thedisk control unit210, and executes the disk heart beatcontrol program215,replication control program217 andstorage control program218, which are comprised of codes for executing various operations according to the present embodiment, and are stored inmemory212. For example, the disk heart beat write unit, disk heart beat detection unit and disk heart beat creation unit are implemented by theCPU211 executing the disk heart beatcontrol program215. Also the replication data transmission unit and the replication data reception unit are implemented by theCPU211 executing thereplication control program217, for example. Also the node heart beat write unit, node heart beat transmission unit and disk heart beat detection result transmission unit are implemented by theCPU211 executing thestorage control program218, for example. In thememory212, the pair management table216 is stored. Details therefore will be described later. The disk heart beatcontrol program215,replication control program217 andstorage control program218 may be independent programs, or at least a part of these programs may be constructed by a same program. Each program may be constructed by a plurality of programs. The FC I/F213 has an interface function for communicating with theinformation processing unit100 or anotherstorage unit200. The disk I/F214 has an interface function for transmitting/receiving data with thedisk drive unit220.

The diskcontrol unit A210 and the diskcontrol unit B210, which are communicably connected via thesecond network310, are also referred to as the storage control system.

Thedisk drive unit220 has astorage volume230 for storing data. Thestorage volume230 is a storage area which includes the physical volume, that is a physical storage area provided by the hard disk drive, and a logical volume that is logically set on the physical volume. InFIG. 1, three storage volumes, LU01, LU02 and LU03 (first storage volume, third storage volume) (230) are shown for the storage unit A (200), and three storage volumes, LU11, LU12 and LU13 (second storage volume) (230) are shown for the storage unit B (200).

Themanagement console260 is an information equipment for maintenance and management of thestorage unit200. Themanagement console260 may be built into thestorage unit200 or may be external. Themanagement console260 may be a computer dedicated to the maintenance and management of thestorage unit200, or may be a general purpose computer which has maintenance and management functions.

FIG. 3 is a block diagram depicting the configuration of themanagement console260. Themanagement console260 is comprised of aCPU261,memory262,port263, recordingmedium reading unit264,input unit265,output unit266 andstorage unit268.

TheCPU261 is in-charge of general control of themanagement console260, and implements the maintenance and management functions of thestorage unit200 by executing thecontrol program269, stored in thememory262, comprised of codes for performing various operations according to the present embodiments. The recordingmedium reading unit264 is a unit for reading the program and data recorded in therecording medium267. The program and data which were read are stored in thememory262 or thestorage unit268. Therefore thecontrol program269, disk heart beatcontrol program215,replication control program217 andstorage control program218, which are recorded in therecording medium267, for example, can be read from therecording medium267 using the recordingmedium reading unit264, and stored in thememory262 or thestorage unit268. For therecording medium267, a flexible disk, CD-ROM, magnetic disk and semiconductor memory, for example, can be used. The recordingmedium reading unit264 may be built into themanagement console260 or may be external. Thestorage unit268 may be a hard disk unit or a semiconductor storage unit, for example. Thecontrol program269 may be stored in thestorage unit268.

Theinput unit265 is a user interface used for data input to themanagement console260 by an operator. For theinput unit265, a keyboard or a mouse, for example, can be used. Theoutput unit266 is a user interface for outputting information to the outside. For theoutput unit266, a display or a printer, for example, can be used. Theport263 is a unit for communicating with theinformation processing unit100 and thestorage unit200. By this, thecontrol program269, disk heart beatcontrol program215,replication control program217 andstorage control program218 can be received from theinformation processing unit100 via theport263, and be stored in thememory262 and thestorage unit268, for example. Also the disk heart beatcontrol program215,replication control program217 andstorage control program218, which are stored in thememory262 and thestorage unit268, can be transmitted to thedisk control unit210 via theport263, and be stored in thememory212 of thedisk control unit210.

The function of themanagement console260 of the present embodiment may be installed in theinformation processing unit100. In some cases themanagement console260 may not be installed. In such cases, the maintenance and management of thestorage unit200 are performed using theinformation processing unit100.

Replication Control

The replication control to be performed by thestorage system400 according to the present embodiment will now be described. Replication control is performed by theCPU211 of thedisk control unit210 executing thereplication control program217. Thestorage volume230 to be the target of replication and the control type of replication are defined in the pair management table216. The pair management table216 can be created based on the data, which is input from theinput unit150 by the operator who operates theinformation unit100, when thestorage management program193 is executed in theinformation processing unit100, for example. If thestorage management program193 is provided to themanagement console260, and theCPU261 of themanagement console260 can execute thestorage management program193, then the pair management table.216 can be created based on the data which is input from theinput unit265 by an operator who operates themanagement console260.

FIG. 4 shows the pair management table216. The pair management table216 is comprised of the “pair type” column, “replication type” column, “replication source unit” column, “replication destination unit” column, “replication source volume” column, “replication destination volume” column and “pair status” column.

A pair refers to a combination ofstorage volumes230 created by the twostorage volumes230. The twostorage volumes230 forming a pair, which are in asame storage unit200, are referred to as “a local pair”, those which are in adifferent storage unit200 are referred to as “a remote pair”. In thestorage volumes230 forming a pair, one is managed as amain storage volume230, and the other is managed as asub-storage volume230. When data is written to themain storage volume230, the replication of the data is written to thesub-storage volume230. For onemain storage volume230, a plurality ofsub-storage volumes230 may be combined.

When theinformation processing unit200 for executing thestorage management program193 instructs the storage unit A (200), which is the data replication source, to create a remote pair, the storage unit A (200) updates the pair management table216. Then the storage unit A (200) instructs the storage unit B (200), which is the data replication destination, to create a remote pair. And the storage unit B (200) updates the pair management table216 of thememory212 in the storage unit B (200).

The “pair type” column of the pair management table216 shows whether this pair is a local pair or remote pair. The “replication type” column shows whether the type of replication is synchronous or asynchronous when this pair is a remote pair. The “replication source unit” column and the replication destinations column show thestorage unit200 at the replication source and thestorage unit200 at the replication destination when this pair is a remote pair. The “replication source volume” column shows the identification number of themain storage volume230 of this pair, and the “replication destination volume” column shows the identification number of thesub-storage volume230 of this pair. For the identification number of thestorage volume230, a LUN (Logical Unit number), for example, can be used.

The “pair status” column shows the status of this pair. The pair status is “pair”, “split” or “re-sync”. In the case of “pair”, the replication of data written from theinformation processing unit100 to themain storage volume230 is also written to thesub-storage volume230. By this, the correspondence of themain storage volume230 and thesub-storage volume230, the sameness of the content stored in themain storage volume230 and the content in thesub-storage volume230, can be assured.

In the case of “split”, data written from theinformation processing unit100 to themain storage volume230 is not reflected on thesub-storage volume230. “re-sync” is a transient status from “split” to “pair”. In other words, this is a status when the update data in themain storage volume230 during “split” is being reflected on thesub-storage volume230. When the reflection completes, the status of this pair becomes “pair”.

The above mentioned pair creation, pair split and pair re-sync can be executed by an operator sending the instructions via theinput unit150 to theinformation processing unit100 where thestorage control program193 is executed. The instruction input from the operator is sent to thedisk control unit210. Thedisk control unit210 executes thereplication control program217, and changes pair formation and pair status according to the above instructions. When the data write request for themain storage volume230 in “pair” status is received from theinformation processing unit100, for example, thedisk control unit210 writes the data to themain storage volume230 according to the pair status of the formed pair, specifies thestorage volume B230 to which the replication of the data is written referring to the pair management table216, and sends the replication of this data to the storage unit B (200). And the storage unit B (200) receives the replication of this data, and writes the replication of this data to thestorage volume B230.

By the above replication control, the data of the computer system at the main system can be stored in the computer system in the remote site.

Cluster Control

The cluster control to be performed by thestorage system400 according to the present embodiment will now be described.

The information processing unit A (100) and the information processing unit B (100) according to the present embodiment performcluster control196 by executing the clustering control program for each other. Cluster control is a control for the computer system at the remote site to take over the information processing which the computer system at the main site has been performing when the computer system at the remote site detects a shut down of the computer system at the main site. Taking over the information processing is also called “fail-over”.

In this case, when the computer system at the remote site detects a shut down of the computer system at the main site, the computer system at the main site normally repeatedly sends predetermined data called “heart beat signals” (heart beat message) to the computer system at the remote site at intervals within a predetermined time. The computer system at the remote site can judge the operation status of the computer system at the main site by detecting the heart beat signal sent from the computer system at the main site. For example, when the computer system at the remote site cannot detect the heart beat signal from the computer system at the main site after waiting a predetermined time, the computer system at the remote site can judge that an abnormality occurred to the computer system at the main site.

Transmission/Reception of Heart Beat Signal

The transmission/reception control of the heart beat signals to be performed in thestorage system400 according to the present embodiment will be described with reference toFIG. 5 toFIG. 14.

FIG. 5 shows a system block diagram depicting the transmission/reception control of the heart beat signals according to the present embodiment. The difference from the system block diagram inFIG. 1 is that a plurality ofinformation processing units100 are in the main site and the remote site respectively in the system block diagram inFIG. 5. In this case, cluster control can be performed in an information processing unit A (100) in the main site by transmitting/receiving heart beat signals with another information processing unit A (100) in the main site, for example. In other words, when an information processing unit A (100) in the main site detects that another information processing unit A (100) in the main site stopped operation, the former information processing unit A (100) in the main site can take over the information processing which the failed information processing unit A (100) has been performing. This is the same for the information processing unit B (100) at the remote site.

The “micro control VOL (VOLume)”, “heart beat PVOL (Primary VOLume)”, “user PVOL”, “heart beat SVOL (Secondary VOLume)” and “user SVOL” arestorage volumes230 respectively. The micro control VOL (230) is astorage volume230 which is used when the transmission/reception of the heart beat signals according to the present embodiment is controlled. In the micro control VOL (230), the heart beat status table194 is stored. Details will be described later.

The heart beat PVOL (230) and the heart beat SVOL (230) constitute a pair in replication, and are themain storage volume230 and thesub-storage volume230 respectively. In the heart beat PVOL (230), the heart beat signals232 are written. Then the replication of the heart beat signal232 is written to the heart beat SVOL (230) which constitute the pair.

The user PVOL (230) and the user SVOL (230) constitute a pair in replication, and are themain storage volume230 and thesub-storage volume230 respectively. In the user PVOL (230), various data, which is generated by theapplication program190 being executed in theinformation processing unit100, is written. Then the replication of the data is written to the user SVOL (230) constituting the pair.

In the transmission/reception of the heart beat signals232 according to the present embodiment, the heart beatcontrol program191 and the node heart beatcontrol program192 are executed by theinformation processing unit100 under the control of theoperating system197, and the disk heart beatcontrol program215,storage control program218 andreplication control program217 are executed by thestorage unit200.

Theoperating system197 provides an API (Application Program Interface) when various programs, such as the heart beatcontrol program191, are executed by theinformation processing unit100. For example, theoperating system197 provides “OPEN”, “READ”, “WRITE” and “CLOSE” for thestorage volume230. In this case, if the node heart beatcontrol program192 writes the heart beat signal232 to the heart beat PVOL (230) of thestorage unit200, for example, “OPEN” is used when the pointer to the heart beat PVOL (230) is acquired, “WRITE” is used when the heart beat signal232 is written, and “CLOSE” is used when the pointer to the heart beat PVOL (230) is relinquished. If the node heart beatcontrol program192 reads the heart beat signal232 from the heart beat SVOL (230) of thestorage unit200, “OPEN” is used when the pointer to the heart beat SVOL (230) is acquired, “READ” is used when the heart beat signal232 is read, and “CLOSE” is used when the pointer to the heart beat SVOL (230) is relinquished.

The heart beatcontrol program191 creates and updates the activation/deactivation message195 and the heart beat status table194 which are stored in thememory120 of theinformation processing unit100, and creates and updates the heart beat status table194 which is stored in themicro control volume230 of thestorage unit200. The activation/deactivation message195 is created and updated based on the data which is input by the operator from theinput unit150 of theinformation processing unit100, for example. The heart beat status table194 can be created and updated based on the content of the activation/deactivation message195, for example. The heart beatcontrol program191, which is executed by theinformation processing unit100 at the remote site, judges the operation status of the computer system at the main site according to the detection result of the heart beatsignal232, which is sent from the computer system at the main site. Details will be described later.

The node heart beatcontrol program192 repeatedly sends a request to write the heart beat signals (second heart beat message, hereafter also called “node heart beat signal232”)232 to the heart beat PVOL (230), to thestorage unit200 at intervals within a predetermined time based on the heart beat status table194 stored in thememory120. This node heart beat signal232 is written to the heart beat PVOL (230) by thestorage unit200. The node heart beatcontrol program192 also sends a request to read the replication of the node heart beat signal232 written in the heart beat SVOL (230) to thestorage unit200 based on the heart beat status table194 stored in thememory120. The replication of this node heart beat signal232 is read from the heart beat SVOL (230) by thestorage unit200, and sent to theinformation processing unit100. And the node heart beatcontrol program192 detects the replication of the node heart beat signal232 which is transmitted from thestorage unit200. And the node heart beatcontrol program192 updates the content of the heart beat status table194 of thememory120. Details will be described later.

The disk heart beatcontrol program215 repeatedly writes the heart beat signals (first heart beat message, hereafter also called “disk heart beat signal232”232 to the heart beat PVOL (230) at intervals within a predetermined time based on the heart beat status table194 stored in the micro control VOL (230). Here the heart beat PVOL (230), to which the disk heart beat signal232 is written by the disk heart beatcontrol program215, may be thesame storage volume230 as the heart beat PVOL (230) to which the node heart beatsignal232, which is transmitted by the node heart beatcontrol program192, is written, or may be adifferent storage volume230. The disk heart beatcontrol program215 also reads the replication of the disk heart beatsignal232, which is written in the heart beat SVOL (230) based on the heart beat status table194 stored in the micro control VOL (230), and detects the replication. And the disk heart beatcontrol program215 updates the content of the heart beat status table194 stored in the micro control VOL (230). Details will be described later.

When the heart beat signal232 is written to the heart beat PVOL (230), thereplication control program217 sends the replication of the heart beat signal232 to thestorage unit200 at the remote site via thesecond network310, based on the pair management table216. Thereplication control program217 receives the replication of the heart beat signal232 which is sent from thestorage unit200 at the main site via thesecond network310, and writes the replication of the heart beat signal232 to the heart beat SVOL (230).

Thestorage control program218 writes the node heart beat signal232 to the heart beat PVOL (230) according to the write request of the heart beatsignal232, which is sent from theinformation processing unit100. Thestorage control program218 also reads the replication of the node heart beat signal232 from the heart beat SVOL (230) according to the read request of the replication of the node heart beat signal232 which is sent from theinformation processing unit100, and sends the replication to theinformation processing unit100. Thestorage control program218 also sends the replication detection result of the disk heart beat signal232 to theinformation processing unit100.

Activation/Deactivation Message

FIG. 6 shows the activation/deactivation message195 according to the present embodiment. As described above, the activation/deactivation message195 is created based on the data which is input by the operator from theinput unit150 of theinformation processing unit100 at the main site. The activation/deactivation message195 is created each time an operator inputs data. In other words, an operator can transmit/receive any number of types of heart beat signals232 between the computer system at the main site and the computer system at the remote site.

The activation/deactivation message195 is comprised of the “activation/deactivation type” column, “disk heart beat/node heart beat type” column, “local device address” column and “remote device address” column.

The “activation/deactivation type” column shows the enabling/disabling transmission/reception of the heart beatsignal232. Enabling transmission/reception of the heart beat signal232 is referred to as activating the heart beatsignal232. Disabling transmission/reception of the heart beat signal232 is referred to as deactivating the heart beatsignal232. The values to be written in the “activation/deactivation type” column can be “ACTIVATE” and “DEACTIVATE”, for example. “ACTIVATE” indicates that the heart beat signal232 is activated, and “DEACTIVATE” indicates that the heart beat signal232 is deactivated.

The “disk heart beat/node heart beat type” column shows whether the heart beat signal232 to be activated or deactivated is the node heart beat signal232 or the disk heart beat signal. The value to be written in the “disk heart beat/node heart beat type” column can be “DISK HEART BEAT” or “NODE HEART BEAT”, for example. “DISK HEART BEAT” indicates that the heart beat signal232 to be activated or deactivated is the disk heart beatsignal232, and “NODE HEART BEAT” indicates that the heart beat signal232 to be activated or deactivated is the node heart beatsignal232.

The “local device address” column shows the address (storage position) of the heart beat PVOL (230) to which the heart beat signal232 is written.

The “remote device address” column shows the address (storage position) of the heart beat SVOL (230) to which the heart beat signal232 is written.

The heart beatcontrol program191 sends the activation/deactivation message195 created based on the data which is input by an operator to theinformation processing unit100 at the remote site. The activation/deactivation message195 may be transmitted to theinformation processing unit100 of the remote site via thefirst network300 or via thesecond network310. To transmit via thesecond network310, replication may be used for the transmission.

Heart Beat Status Table

Then theinformation processing unit100 at the main site and theinformation processing unit100 at the remote site create and update the heart beat status table194 based on the activation/deactivation message195 respectively.FIG. 7 shows the heart beat status table according to the present embodiment.

The heart beat status table194 is comprised of a portion which shows the status of the node heart beat signal232 and the portion showing the status of the disk heart beatsignal232.

The portion showing the status of the node heart beat signal232 is comprised of the “node heart beat status” column, “P/S type” column, “local device address” column, “remote device address” column and “device status” column. One or more “P/S type” columns, “local device address” columns, “remote device address” columns and “device status” columns are created for the number of types of the node heart beat signals232. In other words, the types of the node heart beat signal232 are specified by the combination of the “P/S type” column, “local device address” column and “remote device address” column.

The “node heart beat status” column shows whether the node heart beat signal232 is transmitted/received between the computer system at the main site and the computer system at the remote site. The value to be written in the “node heart beat status” column can be “ENABLE” or “FAILED”. “ENABLE” indicates that at least one type of node heart beat signal232 is being transmitted/received between the computer system at the main site and the computer system at the remote site. “FAILED” indicates that the node heart beat signal232 is not transmitted/received at all.

The “P/S type” column shows whether the node heart beat signal232 is to be transmitted or received. In other words, the “P/S type” column indicates whether the next column, “local device address” is the heart beat PVOL (230) or the heart beat SVOL (230). The value to be written in the “P/S type” column can be “PVOL” or “SVOL”. Theinformation processing unit100, which created the activation/deactivation message195, sets “PVOL” in the “P/S type” column. Theinformation processing unit100, to which the activation/deactivation message195 is transmitted, sets “SVOL” in the “P/S type” column.

The “local device address” column shows an address where the node heart beat signal232 is written in thestorage volume230 of thestorage unit200 in a same computer system. If the “P/S type” column is “PVOL”, the node heart beatsignal232, which is written at the address indicated in the “local device address” column, is sent to anotherstorage unit200 by thereplication control program217. If the “P/S type” column is “SVOL”, the node heart beatsignal232, which is sent from anotherstorage unit200 by thereplication control program217, is written at the address indicated in the “local device address” column.

The “remote device address” column shows an address where the node heart beat signal232 is written in thestorage volume230 of thestorage unit200 in a different computer system.

The “device status” column shows whether the node heart beat signal232 is transmitted/received correctly. The value to be written in the “device status” column can be “ENABLE” or “FAILED”. “ENABLE” indicates that the node heart beat signal231 is being correctly transmitted/received. “FAILED” indicates that the node heart beat signal232 is not being correctly transmitted/received.

If the “device status” column is “FAILED” for all types of node heart beat signals232, this means that the transmission/reception of the node heart beat signal232 is all incorrect, so “FAILED” is written in the “node heart beat status” column.

How to decide whether the node heart beat signal232 is correctly transmitted/received or not will be described later.

The portion indicating the status of the disk heart beat signal232 is comprised of the “disk heart beat status” column, “P/S type” column, “local device address” column, “remote device address” column and “device status” column. One or more “P/S type” columns, “local device address” columns, “remote device address” columns and “device status” columns are created for the number of types of the disk heart beat signals232. In other words, the types of the disk heart beat signals232 are specified by the combination of the “P/S type” column, “local device address” column and “remote device address” column.

The “disk heart beat status” column shows whether the disk heart beat signal232 is being transmitted/received between the computer system at the main site and the computer system at the remote site. The value to be written in the “disk heart beat status” can be “ENABLE” or “FAILED”. “ENABLE” indicates that at least one type of the disk heart beat signals232 is being transmitted/received between the computer system at the main site and the computer system at the remote site. “FAILED” indicates that the disk heart beat signals232 are not transmitted/received at all.

The “P/S type” column, “local device address” column, “remote device address” column and “device status” column are the same as the portion indicating the status of the node heart beatsignal232.

The heart beat status table194 to be stored in the micro control VOL (230) may have only the portion indicating the status of the disk heart beatsignal232. By this, the status of the disk heart beat signal232 can be managed with less storage capacity.

Heart Beat Signal

The node heart beatcontrol program192 creates the node heart beat signal232 and repeatedly sends a request to write the node heart beat signal232 to the heart beat PVOL (230), to thestorage unit200 at intervals within a predetermined time, such as intervals within one minute, based on the heart beat status table194 stored in thememory120. The node heart beat signal232 is written in the heart beat PVOL (230) by thestorage control program218, which is executed by thestorage unit200.

The disk heart beatcontrol program215 creates the disk heart beatsignal232, and repeatedly writes the disk heart beat signal232 to the heart beat PVOL (230) at intervals within a predetermined time, such as intervals within one minute, based on the heart beat status table194 stored in the micro control VOL (230).

FIG. 8 shows the node heart beat signal232 and the disk heart beat signal232 according to the present embodiment. AsFIG. 8 shows, the node heart beat signal232 and the disk heart beat signal232 according to the present embodiment, is comprised of at least one of “serial number” column, “time”column, “disk heart beat/node heartbeat type” column, “local device address” column and “remote device address” column.

The “serial number” column is a column where the identification information for identifying each one of a same type of heart beat signals232 which are written in the heart beat PVOL (230) at intervals within a predetermined time. The serial number can be a number which is incremented by 1 each time the heart beatsignal232, which is sequentially written to the heart beat. PVOL (230), is written.

The “time” column is a column where information indicating the time when the heart beat signal232 was created, by the node heart beatcontrol program192 or the disk heart beatcontrol program215, is written. Time can be the date and time when the heart beat signal232 was created, or can be information indicating the difference from a predetermined reference date and time.

The “disk heart beat/node heart beat type” column is a column where information, indicating whether the signal is the node heart beat signal232 created by the node heart beatcontrol program192 or the disk heart beat signal232 created by the disk heart beatcontrol program215, is written.

The “local device address” column is a column where the information indicating the storage position of the heart beat PVOL (230), to which the heart beat signal232 is written, is written. The “remote device address” column is a column where the information indicating the storage position of the heart beat SVOL (230), to which the heart beat signal232 is written, is written.

Checking Correct Transmission/Reception of Node Heart Beat Signal

The node heart beatcontrol program192, to be executed in theinformation processing unit100 at the remote site, refers to the heart beat status table194, and for the devices of which the “P/S type” column is “SVOL” and the “device status” column is “ENABLE”, the node heart beatcontrol program192 specifies the address written in the “local device address” column respectively, and sends a request to read the replication of the node heart beat signal232 to thestorage unit200. This read request can be sent at every predetermined time, such as at one minute intervals. The replication of this node heart beat signal232 is read from the heart beat SVOL (230) by thestorage unit200, and is sent to theinformation processing unit100. And the node heart beatcontrol program192 judges whether the node heart beat signal232 is being transmitted/received correctly by comparing the content of the replication of the node heart beat signal232 which is read from the heart beat SVOL (230) and the content corresponding to the node heart.beat signal232 in the heart beat status table194.

Specifically, it is compared whether the content written in the “remote device address” column of the node heart beat signal232 matches with the content written in the “remote device address” column corresponding to the node heart beat signal232 in the heart beat status table194, whether the content written in the “local device address” column in the node heart beat signal232 matches with the content written in the “local device address” column corresponding to the node heart beat signal232 in the heart beat status table194, and whether the content written in the “disk heart beat/node heart beat type” column of the node heart beat signal232 is “NODE HEART BEAT”. Also it is checked that the value written in the “serial number” column of the node heart beat signal232 is increased from the value of the node heart beat signal232 received the last time.

The node heart beatcontrol program192 decides that the node heart beat signal232 is being transmitted/received correctly when the node heart beat signal232 matches the contents written in each of the above mentioned columns of the heart beat status table194, and the content written in the “disk heart beat/node heart beat type” column of the node heart beat signal232 is “NODE HEART BEAT”, and the value written in the “serial number” column of the node heart beat signal231 is increased from the value of the node heart beat signal232 received the last time.

According to the decision on whether the node heart beat signal232 is being transmitted/received correctly, the node heart beatcontrol program192 writes “ENABLE” or “FAILED” in the “device status” column of the heart beat status table194.

The node heart beatcontrol program192 writes “FAILED” in the “node heart beat status” column when the “device status” column is all “FAILED” for the portion indicating the status of the node heart beat signal232 of the heart beat status table194.

Checking Correct Transmission/Reception of Disk Heart Beat Signal

The disk heart beatcontrol program215 refers to the heart beat status table194 stored in the micro control VOL (230), and for the devices of which the “P/S type” columns is “SVOL” and the “device status” column is “ENABLE”, the disk heart beatcontrol program215 reads the replication of the heart beat signal232 from the heart beat SVOL (230) written in the “local device address” column respectively. This reading can be executed at every predetermined time, such as at one minute intervals. The disk heart beatcontrol program215 judges whether the disk heart beat signal is being transmitted/received correctly by comparing the content of the replication of the disk heart beat signal232 that is read from the heart beat SVOL (230), and the content corresponding to the disk heart beat signal232 in the heart beat status table194.

Specifically, it is compared whether the content written in the “remote device address” column of the disk heart beat signal232 matches with the content written in the “remote device address” column corresponding to the disk heart beat signal232 in the heart beat status table194, whether the content written in the “local device address” column of the disk heart beat signal232 matches with the content written in the “local device address” column corresponding to the disk heart beat signal232 in the heart beat status table194, and whether the content written in the “disk heart beat/node heart beat type” column of the disk heart beat signal232 is “DISK HEART BEAT”. Also it is checked that the value written in the “serial number” column of the disk heart beat signal232 is increased from the value of the disk heart beat signal232 received the last time.

The disk heart beatcontrol program192 decides that the disk heart beat signal232 is being transmitted/received correctly when the disk heart beat signal232 matches with the content written in each of the above mentioned columns of the heart beat status table194, and the content written in the “disk heart beat/node heart beat type” column of the disk heart beat signal232 is “DISK HEART BEAT”, and the value written in the “serial number” column of the disk heart beat signal232 is increased from the value of the disk heart beat signal232 received the last time.

Then according to the decision on whether the disk heart beat signal232 is being transmitted/received correctly, the disk heart beatcontrol program215 writes “ENABLE” or “FAILED” in the “device status” column of the heart beat status table194.

The disk heart beatcontrol program215 writes “FAILED” in the “disk heart beat status” column when the “device status” column is all “FAILED” for the portion indicating the status of the disk heart beat signal232 of the heart beat status table194.

Judging Operation Status of Computer System at Main Site

The heart beatcontrol program191 to be executed in theinformation processing unit100 at the remote site transmits the read request of the heart beat status table194 stored in the micro control VOL (230) to thestorage unit200 at the remote site. This read request can be transmitted at every predetermined time, such as at one minute intervals. And thestorage unit200 sends the heart beat status table194 stored in the micro control VOL (230) to theinformation processing unit100. The heart beatcontrol program191 reflects the portion indicating the status of the disk heart beat signal232 out of the heart beat status table194 sent from thestorage unit200 in heart beat status table194 stored in thememory120. And the heart beatcontrol program191 checks whether the node heart beat signal232 and the disk heart beat signal232 are being correctly transmitted/received between the computer system at the main site and the computer system at the remote site. By this, the heart beatcontrol program191 judges the operation status of the computer system at the main site according to the detection result of the replication of the disk heart beat signal232 and the detection result of the replication of the node heart beatsignal232.

Theinformation processing unit100 at the remote site also judges whether it is necessary to execute fail-over according to the operation status of the computer system at the main site, and if necessary, the information processing in the computer system at the main site is transferred to the computer system at the remote site. The fail-over can be executed by theclustering control program196. Details will be described later.

Activation/Deactivation of Heart Beat Signal

Now the processing flow to activate the heart beat signal232 and the processing flow to deactivate the heart beat signal232 will be described. At first, the processing flow to activate the heart beat signal232 will be described with reference to the flow chart shown inFIG. 9.

First, the heart beatcontrol program191 creates an activation/deactivation message195 based on the data which an operator input to theinput unit150 of theinformation processing unit100 at the main site.

If the instruction from the operator is to activate the heart beatsignal232, the heart beatcontrol program191 checks whether the mirror for the heart beat has been generated (S1000). The mirror for the heart beat is the heart beat PVOL (230) and the heart beat SVOL (230) where the replication pair is formed. If the mirror for the heart beat is not generated, the mirror for the heart beat is generated (S1001). The mirror for the heart beat may be generated by thereplication control program217.

When the mirror for the heart beat is generated, the heart beatcontrol program191 updates the heart beat status table194 stored in thememory120 of theinformation processing unit100 at the main site (S1002). For example, the “node heart beat status” column of the heart beat status table194 is changed to “ENABLE”. The production site which is written inFIG. 9 and other drawings is the main site. The standby site is the remote site.

Then the heart beatcontrol program191 checks whether an operator instructed activation for the disk heart beat. signal232 (S1003). If activation is instructed for the disk heart beatsignal232, processing advances to “YES”, and the heart beat status table194 stored in the micro control VOL (230) is updated (S1004). For example, the “disk heart beat status” column of the heart beat status table194 is changed to “ENABLE”.

And the heart beatcontrol program191 sends the activation/deactivation message195 to the computer system at the remote site (S1005). The heart beatcontrol program191 to be executed in theinformation processing unit200 of the computer system at the remote site updates the heart beat status table194 in the computer system at the remote site according to the procedure described above (S1006).

Now the processing flow to deactivate the heart beat signal232 will be described with reference to the flow chart inFIG. 10.

At first, the heart beatcontrol program191 creates an activation/deactivation message195 based on the data which an operator input to theinput unit150 of theinformation processing unit100 at the main site.

If the instruction from the operator is to deactivate the heart beatsignal232, the heart beatcontrol program191 updates the heart beat status table194 stored in thememory120 of theinformation processing unit100 at the main site (S2000). For example, the “node heart beat status” column of the heart beat status table194 is changed to “FAILED”.

Then the heart beatcontrol program191 checks whether the operator instructed deactivation for the disk heart beat signal232 (S2001). If deactivation is instructed for the disk heart beatsignal232, processing advances to “YES”, and the heart beat status table194 stored in the micro control VOL (230) is updated (S2002). For example, the “disk heart beat status” column of the heart beat status table194 is changed to “FAILED”.

And the heart beatcontrol program191 sends the activation/deactivation message195 to the computer system at the remote site (S2003). The heart beatcontrol program191 to be executed in theinformation processing unit200 of the computer system at the remote site updates the heart beat status table194 in the computer system at the remote site according to the procedure described above (S2004).

And the heart beatcontrol program191 checks whether an unnecessary mirror for the heart beat exists (S2005). If an unnecessary mirror for the heart beat exists, it is deleted (S2006). The unnecessary mirror for the heart beat may be deleted by thereplication control program217.

Transmission of Node Heart Beat Signal

When the node heart beat signal232 is activated by the above processing, transmission of the node heart beat signals232 from the computer system at the main site to the computer system at the remote site starts. The processing flow when the node heart beat signal232 is transmitted will be described with reference to the flow chart inFIG. 11.

At first, the node heart beatcontrol program192 refers to the portion indicating the status of the node heart beat signal232 in the heart beat status table194 stored in thememory120, and specifies the address of the heartbeat PVOL (230) written in the “local device address” column for the devices of which the “P/S type” column is “PVOL” and the “device status” column is “ENABLE” (S3000). And the node heart beatcontrol program192 specifies the address of the heart beat PVOL (230), and sends the write request of the node heart beat signal232 to thestorage unit200. This node heart beat signal232 is written to the heart beat PVOL (230) by thestorage control program218 which is executed in the storage unit200 (S3001). And thereplication control program217 sends the node heart beat signal232 written in the heart beat PVOL (230) to thestorage unit200 at the remote site via thesecond network310 based on the pair management table216. Thereplication control program217 writes the node heart beat signal232 transmitted from thestorage unit200 at the main site to the heart beat SVOL (230) via the second network310 (S3002). By this, the node heart beat signal232 can be sent from the computer system at the main site to the computer system at the remote site. The remote mirror written inFIG. 11 and other drawings is thereplication control program217.

The above processing is executed for each device of which the “P/S type” column is “PVOL” and the “device status” column is “ENABLE” in the portion indicating the node heart beat signal232 status of the heart beat status table194 stored in thememory120.

Transmission of Disk Heart Beat Signal

When the disk heart beat signal232 is activated, the transmission of the disk heart beat signal232 from the computer at the main site to the computer at the remote site starts. The processing flow when the disk heart beat signal232 is transmitted will be described with reference to the flow chart inFIG. 12.

At first, the disk heart beatcontrol program215 refers to the portion indicating the status of the disk heart beat signal232 out of the heart beat status table194 stored in the micro control VOL (230), and specifies the address of the heart beat PVOL (230) written in the “local device address” column for the devices of which the “P/S type” column is “PVOL” and the “device status” column is “ENABLE” (S4000). And the disk heart beatcontrol program215 writes the disk heart beat signal232 to the address of the heart beat PVOL (230) (S4001). And thereplication control program217 sends the disk heart beat signal232 written in the heart beat PVOL (230) to thestorage unit200 at the remote site via thesecond network310 based on the pair management table216. Thereplication control program217 writes the disk heart beat signal232 transmitted from thestorage unit200 at the main site to the heart beat SVOL (230) via thesecond network310. By this, the disk heart beat signal232 can be sent from the computer system at the main site to the computer system at the remote site.

The above processing is executed for each device of which the “P/S type” column is “PVOL” and the “device status” column is “ENABLE” in the portion indicating the disk heart beat signal232 status of the heart beat status table194 stored in the micro channel VOL (230).

Reception of Disk Heart Beat Signal

The processing flow when the disk heart beat signal232 is received will now be described with reference to the flow chart shown inFIG. 13.

At first, as described above, the disk heart beatcontrol program215 compares the content, written in the heart beat status table194, stored in the micro control VOL (230), and the content of the disk heart beat signal232 written in the heart beat SVOL (230), and checks whether the disk heart beat signal232 is normal (S5000). If the disk heart beat signal232 is abnormal, processing advances to “NO” in S5001, and the content of the heart beat status table194 stored in the micro control VOL (230) is updated (S5002). This update is executed by writing “FAILED” in the “device status” column of the heart beat status table194.

Reception of Node Hart Beat Signal

The processing flow when the node heart beat signal232 is received will now be described with reference to the flow chart shown inFIG. 14.

At first, as described above, the node heart beatcontrol program192 sends the request to read the replication of the node heart beat signal232 written in the heart beat SVOL (230) to thestorage unit200 based on the heart beat status table194 stored in thememory120. This replication of the node heart beat signal232 is read from the heart beat SVOL (230) by thestorage control program218 executed by thestorage device200, and is sent to theinformation processing unit100. And the node heart beatcontrol program192 compares the content written in the heart beat status table194 stored in thememory120 and the content of the node heart beatsignal232, and checks whether the node heart beat signal232 is normal (S6000). If the node heart beat signal232 is abnormal, processing advances to “NO” in S6001, and the content of the heart beat status table194 stored in thememory120 is updated (S6002). This update is executed by writing “FAILED” in the “device status” column of the heart beat status table194.

The heart beatcontrol program191, on the other hand, sends the request, to read the heart beat status table194 stored in the micro control VOL (230), to thestorage unit200. The heart beatcontrol program191 reflects the portion indicating the status of the disk heart beatsignal232, out of the heart beat status table194 transmitted by thestorage control program218 which is executed in thestorage unit200, in the heart beat status table194 stored in the memory120 (S6003). The heart beatcontrol program191 judges the operation status of the computer system at the main site, and specifies the failure area (S6004).

The failure area can be specified by referring to the heart beat decision table198 shown inFIG. 15, for example. InFIG. 15, the node heart beat signal232 in “OK” is a status where the “node heart beat status” column of the heart beat status table194 is “ENABLE”. The node heart beat signal232 in “NG” is a status where the “node heart beat status” column of the heart beat status table194 is “FAILED”. This is the same for the disk heart beatsignal232.

Depending on whether the node heart beat signal232 or the disk heart beat signal232 was transmitted/received normally, the result is classified into one of “1”, “2”, “3” and “4” of the heart beat decision table198, and the failure area is specified.

For example, in thestorage system400 with the configuration shown inFIG. 16, the failure area can be specified as shown inFIG. 17 when the node heart beat signal232 or the disk heart beat signal232 is transmitted/received.

FIG. 17 shows that the area indicated by a circle is not abnormal, and the area indicated by a black triangle is potentially abnormal. For example, if the node heart beat signal232 is transmitted/received normally but the disk heart beat signal232 is not correctly transmitted/received, for example, this status is classified as “3” in the heart beat decision table198 inFIG. 15, so it is immediately decided that thedisk control unit210 of thestorage unit200 at the main site is abnormal. If the disk heart beat signal232 is correctly transmitted/received, but the node heart beat signal232 is not correctly received, for example, this status is classified as “2” in the heart beat decision table198 inFIG. 15, so it is immediately decided that theinformation processing unit100 at the main site is abnormal, or the input/output path330 connecting theinformation processing unit100 and thestorage unit200 at the main site is abnormal.

Also in thestorage system400 with the configuration shown inFIG. 18, the failure areas can be specified in detail, as shown inFIG. 19.

If a plurality of node heart beat signals232 are transmitted/received as shown inFIG. 20, the failure area can be specified in even more detail. The heart beat decision table198 in this case is as shown inFIG. 21. And depending on whether the node heart beat signal232 and the disk heart beat signal232 were transmitted/received normally respectively, the result is classified into one of “1” to “8” in the heart beat decision table198, and the failure area can be specified in detail.

When the failure area is specified as above, the heart beatcontrol program191 outputs the operation status of the computer system at the main site to the user interface. And the heart beatcontrol program191 executes processing according to the failure area (S6005). The operation status can be output through the window which is displayed on the screen of the display, that is theoutput unit160 of theinformation processing unit100. Theoutput unit266 of themanagement console260 may also be implemented through the window which is displayed on the screen of the display. In thestorage system400 of the present embodiment, the failure area is immediately specified and is output to the user interface, so the failure area can be quickly specified, burden on maintenance and management can be decreased, and the reliability of the computer system can be improved.

The heart beatcontrol program191 can decide whether a fail over is executed according to the failure area, for example, and can have theclustering control program196 executes a fail over if necessary. For example, in the configuration of thestorage system400 shown inFIG. 20, if the disk heart beat signal232 is correctly transmitted/received but the two node heart beat signals232 are not transmitted/received normally for either case, then whether an abnormality occurred at an area indicated by a black triangle is checked one by one by executing a diagnostic program, and a fail over is performed when it is finally decided that an abnormality occurred to theinformation processing unit200 at the main site.

In this way, according to thestorage system400 of the present embodiment, the computer system at the remote site can detect the occurrence of an abnormality to thestorage unit200 at the main site by detecting that the disk heart beat signal232 is not transmitted from the computer system at the main site. By this, an abnormality of thestorage unit200 at the main site can be detected and specified more quickly. This makes it possible to handle a failure quickly, decrease the burden of maintenance and management, improve the maintenance service, and improve the reliability of the computer system.

In thestorage system400 according to the present embodiment, the transmission/reception of the node heart beat signal232 is combined in addition to the transmission/reception of the disk heart beatsignal232, so it is possible to specify the failure area of the computer system more easily, in more detail, and more accurately. Also when cluster control is performed, the operation when failure is detected can be specified. For example, when the “node heart beat status” of the heart beat status table194 is “FAILED” and the “disk heart beat status” is “ENABLED”, it is judged that information processing cannot be continued in the information processing unit A (100)) at the main site, and processing can be switched to the processing in the information processing unit B (100) at the remote site. In this way, even in a case when the information processing service cannot be continued in prior art, the information processing service can be continuously provided.

Thestorage system400 according to the present embodiment transmits/receives these heart beat signals232 via the highly reliablesecond network310, so reliability. can be improved.

Preferred embodiments of the present invention were described above, but the above mentioned embodiments were to make it easier to understand the present invention, and do not restrict the interpretation of the present invention. The present invention can be changed and improved within the scope of the essential character thereof, and the present invention includes equivalents thereof.

Claims (14)

1. A storage system, comprising:

a first storage unit having a first storage volume for storing data; and

a second storage unit communicably coupled to the first storage unit and having a second storage volume for storing data, wherein

the first storage unit includes a data transmission unit configured to transmit replicated data to a storage unit when data is written to the first storage volume;

the second storage unit further includes a data reception unit configured to receive the replicated data and writing the replicated data to the second storage volume;

the first storage unit further includes a disk heart beat write unit configured to repeatedly write a first heart beat message to the first storage volume at intervals within a predetermined time; and

the second storage unit further includes a disk heart beat detection unit configured to detect a replication of the first heart beat message to be written to the second storage volume by the data reception unit;

wherein

a first information processing unit is communicably coupled to the first storage unit,

a second information processing unit is communicably coupled to the second storage unit,

the first information processing unit further comprises a node heart beat write request unit configured to repeatedly transmit a request to write a second heart beat message to the first storage volume, to the first storage unit at intervals within a predetermined time,

the first storage unit further comprises a node heart beat write unit configured to write the second heart beat message to the first storage volume according to the write request of the second heart beat message,

the second storage unit further includes a node heart beat transmission unit configured to transmit a replication of the second heart beat message to be written to the second storage volume by the data reception unit to the second information processing unit, and

the second information processing unit further comprises a node heart beat detection unit configured to detect the replication of the second heart beat message to be transmitted by the node heart beat transmission unit.

2. The storage system according toclaim 1, wherein the first storage unit further comprises a disk heart beat creation unit configured to create disk heart beat signals to provide the first heart beat message.

3. The storage system according toclaim 1, wherein the first information processing unit further comprises a node heart beat creation unit configured to create node heart beat signals to provide the second heart beat message.

4. The storage system according toclaim 1, wherein:

the second storage unit further includes a disk heart beat detection result transmission unit configured to transmit a detection result of the replication of the first heart beat message by the disk heart beat detection unit to the second information processing unit, and

the second information processing unit further includes an operation status decision unit configured to determine operation status of a first computer system, the first computer system including the first information processing unit and the first storage unit, using detection of the first heart beat message and the second heart beat message.

5. The storage system according toclaim 4, wherein the second information processing unit further comprises a fail-over control unit which transfers information processing from the first computer system to a second computer system, the second computer system including the second information processing unit and the second storage unit depending upon operation status of the first computer system.

6. The storage system according toclaim 4, wherein

the second information processing unit further comprises an operation status display unit configured to provide the operation status of the first computer system to a user interface.

7. The storage system according toclaim 1, wherein the first heart beat message includes at least one of: (1) identification information of the first heart beat message, (2) time information indicating when the first heart beat message was created, (3) first location information indicating a storage position of the first storage volume where the first heart beat message is written, and (4) second information indicating the storage position of the second storage volume where the first heart beat message is written.

8. A method for controlling a storage system which system includes a first storage unit having a first storage volume for storing data, and a second storage unit in communication with the first storage unit and having a second storage volume for storing data, wherein the first storage unit includes a data transmission unit configured to transmit replicated data to the second storage unit when the data is written to a first storage volume, and the second storage unit includes a data reception unit configured to receive the replicated data and writing the replicated data to the second storage volume, wherein a first information processing unit communicates with the first storage unit and a second information processing unit communicates with the second storage unit, the method comprising:

creating disk heart beat signals at the first storage unit to provide a first heart beat message;

creating node heart beat signals at the first information processing unit to provide a second heart beat message;

in the first storage unit, repeatedly writing the first heart beat message to the first storage volume at intervals;

in the second storage unit, detecting replicated first heart beat message to be written to the second storage volume;

repeatedly transmitting from the first information processing unit a request to write a second heart beat message to the first storage volume;

writing the second heart beat message to the first storage volume;

transmitting from the second storage unit to the second information processing unit a replication of the second heart beat message; and

at the second information processing unit, detecting the replication of the second heart beat message.

9. The method according toclaim 8, further comprising:

from the second storage unit, transmitting a detection result of the first heart beat message to the second information processing unit; and

at the second information processing unit, determining operational status of a first computer system which includes the first information processing unit and the first storage unit using reception of the first heart beat message and the second heart beat message.

10. The method according toclaim 9 further comprising transferring information processing from the first computer system to a second computer system which includes the second information processing unit and the second storage unit according to the operational status of the first computer system.

11. The method according toclaim 9 further comprising at the second information processing unit providing the operational status of the first computer system to a user interface.

12. The method according toclaim 8, wherein the first heart beat message comprises at least one of: (1) identification information of the first heart beat message; (2) time information indicating when the first heart beat message was created; (3) information indicating a storage position of the first storage volume; and (4) information indicating a storage position of the second storage volume.

13. A storage system comprising:

a first computer system including a first storage unit having a first storage volume for storing data, and a first information processing unit communicably coupled to the first storage unit; and

a second computer system including a second storage unit having a second storage volume for storing data, and a second information processing unit communicably coupled to the first storage unit; wherein

the first storage unit includes a data transmission unit configured to transmit replicated data to the second storage unit when the data is written to the first storage volume,

the second storage unit includes a data reception unit configured to receive the replicated data and writing the replicated data to the second storage volume,

the first storage unit includes a disk heart beat creation unit configured to repeatedly create a first heart beat message, and a disk heart beat write unit configured to repeatedly write the first heart beat message to the first storage volume at intervals;

the second storage unit further includes a disk heart beat detection unit configured to detect the replicated first heart beat message, and a disk heart beat detection result transmission unit configured to transmit a signal indicating receipt of the replicated first heart beat message by the disk heart beat detection unit to the second information processing unit;

the first information processing unit includes a node heart beat creation unit configured to repeatedly create a second heart beat message, and a node heart beat write request unit configured to repeatedly transmit a request to write the second heart beat message to the first storage volume;

the first storage unit includes a node heart beat write unit configured to write the second heart beat message to the first storage volume according to the write request of the second heart beat message;

the second storage unit includes a node heart beat transmission unit configured to transmit to the second information processing unit the replication of the second heart beat message written to the second storage volume by the data reception unit;

the second information processing unit includes a node heart beat detection unit configured to detect the replication of the second heart beat message, and an operation status unit configured to determine operational status of the first computer system according to the second heart beat message and the first heart beat message, and a fail-over execution unit configured to transfer information processing from the first computer system to the second computer system according to the operational status of the first computer system.

14. The storage system according toclaim 13, wherein:

the first heart beat message includes at least one of: (1) identification information of the first heart beat message, (2) time information indicating when the first heart beat message was created, (3) information indicating a storage position of the first storage volume, and (4) information indicating a storage position of the second storage volume; and

the second heart beat message includes at least one of: (1) identification information of the second heart beat message, (2) time information indicating when the second heart beat message was created, (3) information indicating a storage position of the first storage volume, and (4) information indicating a storage position of the second storage volume.

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